Tell her to hang in there, from us. Cats that have been neglected or not properly socialized are tough to crack, and if the poor baby is naturally a bit nervous ( like my Jarvis) it is even tougher.
Our boy Jarvis was not neglected, just nervy and sent home too young. It sounds like your friend's cat is in a worse place than our baby was.
Ask as many questions as you or she need, happy to help any way we can. As a frame of reference, Jarvis lashed out, biting and scratching me, for several months after he came home out of fear of me. Once we got a handle on that, and figured out why he was doing it, we made great inroads, but also as mentioned by others, Mickey, our youngest boy, was the key that unlocked Jarvis- a confident, happy little kitten that was more likely to climb me or take a nap in my arms than run or lash out in fear. In many ways, Mickey was Jarvis "aha" moment, and in many others, the catalyst for the "aha" moment.